No, not all biology texts that predate Darwin's work are considered pseudoscience. While Charles Darwin's theory of evolution by natural selection revolutionized the field of biology, it does not render all earlier biological studies and texts as pseudoscience.
Before Darwin, there were various scientific and philosophical ideas about the origins and diversity of life. These ideas were based on the scientific knowledge and understanding available at the time, although they may not have had the benefit of the comprehensive evidence and explanatory power that Darwin's theory later provided.
Some earlier theories, such as Jean-Baptiste Lamarck's theory of inheritance of acquired characteristics, which suggested that traits acquired during an organism's lifetime could be passed on to offspring, are now considered outdated and inconsistent with our current understanding of genetics. However, they were not pseudoscience at the time but rather attempts to explain the complexity of life based on the knowledge available.
It's important to remember that scientific knowledge evolves over time as new evidence and theories emerge. The scientific community continually builds upon previous work, refining and expanding our understanding of the natural world. While Darwin's theory of evolution is now widely accepted and forms the foundation of modern biology, earlier biological texts can still hold historical and scientific value, providing insights into the development of scientific thinking and the understanding of life before Darwin's contributions.